Island



(No Model.)

J. F. GRAY.

STEAM BOILER.

$10 433,405. Patented July 29, 1890.

clear, and exact UNITED STATES PATENT OFFICE.

JOHN F. GRAY, OF PROVIDENCE, RHODE ISLAND.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent N 0. 483,405, dated July29, 1890. Application filed January 20, 1890. Serial No. 337,482. (Nomodel.)

To all whom it may concern.-

Be it known that I, JOHN F. GRAY, of Providence, in the county ofProvidence, State of Rhode Island, have invented certain new and usefulImprovements in Boilers, of which the following is a descriptionsufficiently full, to enable any person skilled in the art or science towhich said invention appertains to make and use the same, refer.- encebeing had to the accompanying drawlngs, forming part of thisspecification, in which Figure 1 is a vertical transverse section of myimproved boiler, and Fig. 2 a central vertical longitudinal section ofthe same.

Like letters and figures of reference indicate corresponding parts inboth figures of the drawings.

My invention relates especially to improvements in water-jackets forsteam heating apparatus, being designed as an improvement on the boilershown in United States Letters Patent No. 394,852, dated December 18,1888, granted to me for new and useful improvements in boilers; and itconsists in certain novel features hereinafter fully set forth andclaimed, the object being to produce a simpler, cheaper, and moreeffective device of this character than is now in ordinary use.

The nature and operation of the improvement will be readily understoodby all conversant with such matters from the following explanation.

In the drawings, A represents the main boiler, and B the supplementalboiler or waterjacket. A cylinder D is incased in brickwork E, whichforms a furnace provided with a chimney b at its forward end. Thecylinder D forms the fire-box and ash-pit and the outer wall of thejacket 13. A horizontallyarrauged grate f is supported on lugs g,disposed centrally in the cylinder. A metallic plate 71, nearlysemicircular in cross-section, issecured to the inner walls of thecylinder at the lugs g, and forms the inner wall of the water-jacket B,the ends of said jacket being closed by the ends of said plate, whichare bent or curved upward to meet the cylinder D and form heads 1' forthe jacket. The mouth of the fire-box and ash pit above and below thegrate f is closed by doors or p. The

inner end of the grate rests on a back piece q, and the space betweensaid back piece and the inner end of the cylinder is bricked in at r tocause the heat to be directed upward against the jacket.

The main boiler A is mounted in the furnace E, directly above the jacketB and is connected therewith by a series of vertical circulation-pipest, any desired number of which may be employed.

'lhe'boiler A has a series of horizontal tubes 1) in the usual manner,and a steam-chamber 10, into which a steam-eduction pipe a; opens. Atransversely-arranged wall 15 in the rear of the furnace supports theinner end of the boiler proper. The space between the inner end of thejacket B and said wall forms a chamber 16, in which metallic oven 17 isdisposed in such manner that the hot air from the firebox will passcompletely around said oven. A horizontal partition 18, connecting thetop of the oven and jacket, prevents the air from passing directly overthe jacket,a flue 25 being thus formed around said oven.

The oven is designed to be used for baking or cooking purposes and opensthrough the furnace-walls, being provided with a door 19 at each end. Adraft-flue 20 opens through the side of the furnace into the ash-pit ofthe fire-box, and is provided with a door 21. A feed-pipe 22 leads intothe jacket for supplying it with Water, which passes through theconnecting-pipes t into the boiler A.

In the use of my improvement water is introduced into the jacket throughthe feedpipe, and passing through the circulationpipes 15 rises into theboiler A. 'Fire being started in the fire-box, the hot air and productsof combustion pass through the rear end thereof and impinge against theadjacent wall of the oven, and being deflected downward thereby passesthrough the flue 25 over the oven and water-jacket into the smokebox 26,thence through the boiler-tubes into smoke-box 27 and over the boiler Ainto chimney b. The oven being directly in the path of the hot air israpidly heated thereby.

The circulation-pipes t are formed in sections coupled together, so thatthey may readily be detached when it becomes necessary to replace thewater-jacket or repair the boiler.

It will be seen that the evaporation-surface in my improved boiler isgreatly in excess of those of ordinary construction.

By forming the outside plate of the jacket and the fire-box of acontinuous cylinder and ri vetin g the inner plate of said jacketthereto, as described, these parts are greatly strengthened and renderedless liable to leak or open out by pressure. Moreover the inner platecan be readily replacedon the cylinder when burned away, and thus avoidthe necessity of substituting an entirely new jacket.

Having thus explained my invention what I claim is- 1. A combinedfire-box and water-jacket, comprising a metallic cylinder having asemicylindrical inner plate secured to the upper half thereof forming awater-jacket with said cylinder, substantially as described.

2. The cylinder D, provided withthe grate f, in combination with theplate h, riveted to the cylinder and forming the jacket B, thecirculation-pipes t, and feed 22, arranged substantially as and for thepurpose set forth.

JOHN F. GRAY.

Witnesses:

K. DURFEE, O. M. SHAW.

